The present invention relates to a bedding foundation and in particular to a foundation having hinged wire form members supporting a wire grid above a support frame.
Bedding foundations come in a variety of forms. In a box spring foundation, a rectangular wire grid is mounted to and spaced above a rectangular support frame by a plurality of spring elements. The spring elements between the wire grid and support frame provide for resilient deflection of the wire grid in the vertical direction.
Other foundations are fabricated with a rectangular wire grid mounted to and spaced above a support frame by rigid support members that do not permit significant vertical deflection of the wire grid relative to the support frame. A padding material such as foam rubber is used to cushion the top of the wire grid for comfort. Such an foundation provides a firm support for a mattress. In addition, the total quantity of wire required in the foundation is reduced, thereby reducing the cost of the foundation assembly.
Bedding foundations are often produced in a two step process. A first manufacturer produces the wire components of the foundation, i.e. the wire grid and springs or support members and possibly the lower support frame. These are then shipped to a bedding manufacturer where the padding and upholstery are applied to complete the foundation production. However, the nature of a bedding foundation results in a large volume of space being occupied during shipment from the wire manufacturer to the bedding manufacturer. To reduce the space required for shipping, two approaches have been taken.
One approach has been to produce a subassembly consisting of the wire grid and springs or support members. The springs or support members are configured so that the subassembly is stackable with the springs or support members of one subassembly being nested into those of the subassembly therebelow. Once the subassemblies are received by the bedding manufacturer, the wire subassemblies are then mounted to support frames to complete the foundation structure which is subsequently padded and upholstered. An example of a such a stackable foundation is shown in U.S. Pat. No. 5,052,064, issued to Hagemeister et al. One disadvantage of stacking the wire subassemblies is that the wire grid and springs or support members must be configured to provide openings from above for nesting. This can result in a less than optimum arrangement of the grid wires or spring locations.
The other approach to reducing the shipping height of the foundation is to attach the wire subassembly to the support frame in a manner that enables the foundation to be collapsed to lower the wire grid directly onto the support frame. Once received by the bedding manufacturer, the wire grid is raised above the support frame and additional support members, which were previously unattached to the support frame, are then attached to fix the wire grid in spaced relationship above the support frame to prevent collapse of the wire grid.
An example of a foldable or collapsible foundation is shown in U.S. Pat. No. 4,377,279 issued to Schulz, Jr. The support members in the Schulz, Jr., patent are hingedly secured to the upper wire grid and to the bottom support frame to permit the foundation to be reduced in height by rotating the support members from a vertical position to a near horizontal position, thus lowering the wire grid to the support frame. To complete the assembly, the wire grid is raised, moving the support members to planes substantially normal to the planes of the wire grid and the support frame. To hold the wire grid spaced above the support frame, a plurality of struts inclined between the wire grid and the support frame are then attached to the support frame. At least one of the struts is inclined in the opposite direction from at least one other strut to provide support in both directions of movement provided by the hinged attachments of the support members.
A disadvantage of this approach is the need for two different support members, one for vertical support, and the other, the inclined struts, solely to prevent collapse. Furthermore, by attaching the inclined struts to the frame after shipping, the equipment for making the attachments is needed at two locations, at the wire manufacturer for attaching the hinged support members and at the bedding manufacturer for attaching the inclined struts.
Accordingly, it is an object of the present invention to provide a bedding foundation which can be shipped in compact stacks and which overcomes the disadvantages found in the prior art.
The foundation of the present invention includes a wire subassembly of the grid and support members but, instead of nestably stacking the subassemblies, the support members are hingedly attached to produce a compact stack. The subassemblies are shipped separate from the support frames. The support members used to mount the grid above the support frame are hinged to the grid wires for rotation between folded and standing positions and include leg portions. In the folded position, the leg portions are positioned against the grid and, when the support members are in the standing position, the leg portions extend downward from the grid.
In the standing position of the support members, the leg portions are not normal to the grid as in the Schulz, Jr. patent but instead are inclined relative to the wire grid at an angle less than ninety degrees. Half of the leg portions are inclined in one direction with the other half inclined in the opposite direction. When the assembly is completed, the oppositely directed leg portions cooperate with one another to hold the wire grid rigidly positioned above the support frame. Thus, the additional struts shown in the Schulz, Jr., patent are no longer needed. In addition, the need for equipment to attach the support members to the frame is only needed at one location, the bedding manufacturer's. Because the wire subassemblies are not stacked as in Hagemeister et al., the grid wires can be located where needed for the desired support, not for nestably stacking the wire subassemblies.
It is a feature of the support members that plural identical support members are attached to the grid in a common orientation and which act together to provide rigid support of the grid. No separate members are needed to prevent collapse of the foundation due to the hinged support member attachment. Only one configuration of support members is used.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.